It is of course known to employ zinc electroplating solutions for purposes of depositing corrosion resistant and decorative plating deposits upon a variety of substrates as exemplified by iron, steel and the like. In order to enhance the brightness of the plating deposit, a variety of additive agents have heretofore been proposed or used. Typical of such brightening and/or additive agents are those disclosed in U.S. Pat. Nos. 3,853,718; 3,974,045 and 4,045,306. It is conventional commercial practice to employ a plurality of such brightening agents in a zinc plating bath in order to attain the desired characteristics of the deposit.
A continuing problem associated with zinc plating baths of the types heretofore known is the inability to produce consistently fully bright zinc deposits over broad operating pH ranges and over a broad range of current densities. Additionally, the deposition of a zinc plate of high ductility has also heretofore been difficult to attain.
The zinc plating bath and process of the present invention overcomes many of the problems and disadvantages associated with prior art solutions and techniques by providing a zinc plating bath featuring a brightening agent which enhances the flexibility and versatility of the bath and producing excellent fully bright zinc deposits over broad pH and current density ranges, while at the same time producing a zinc deposit which has excellent ductility characteristics.